|
[Sponsors] |
January 26, 2012, 03:22 |
y+Factor: Help understanding?
|
#1 |
Senior Member
Join Date: Dec 2010
Posts: 135
Rep Power: 15 |
Hi guys
I really have a problem understanding the wall y+ factor and its`range. Am I right, that the y+ factor is a number which shows the code when to switch between far field and wall treatment functions? In Star-CCM+ are three different types fo Wall-treatments I could choose implmented: High-Reynolds wall treatment, Low-Reynolds wall treatment and All-Two-Layer Treatment (mix of High and Low-Re). 1st question: What is the range of high- and or low Reynolds models? 2nd question: What is the range of wall y+: In the User Guide I found for ke-Model realizabel a range for high Reynolds y+ > 30 and for low-Re y~1, 2Layer: y+ ~30-50. -> This means if I have got an y+ value of 8 on a surface (ke_Modell RLZ:All-Layer Treatment), i need to optimize the mesh on surface so that the y+ factor is 30 in minumum? |
|
January 26, 2012, 16:45 |
|
#2 |
Senior Member
Join Date: Mar 2009
Location: Austin, TX
Posts: 160
Rep Power: 18 |
The Star-CCM+ "All y+" model is useful because you do not have to go through your model and specify which walls use a low Reynolds approach and which use a high y+ wall function. The model does not promise any sort of accuracy in the range of 1<y+>30. You should have the bulk of your y+ values be either <1 or between something like 20 and 200.
|
|
January 26, 2012, 17:23 |
|
#3 | |
Senior Member
Join Date: Dec 2010
Posts: 135
Rep Power: 15 |
Quote:
|
||
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Understanding Code behind BCs | Linse | OpenFOAM Programming & Development | 8 | January 9, 2012 09:58 |
Ambiguity in understanding interfaces in CFX | saisanthoshm88 | CFX | 9 | February 2, 2011 15:05 |
Is this understanding of turbulence models correct? | 3kha | Main CFD Forum | 3 | January 31, 2011 22:31 |
Problem understanding rhoPisoFoam | MatP | OpenFOAM Running, Solving & CFD | 1 | May 15, 2010 14:21 |
Understanding of channelOodles and oodles solver | fs82 | OpenFOAM | 1 | September 23, 2009 11:36 |